Henry S. Clark (January 19, 1904 - February 6, 1999) was an American Hall of Fame horse trainer. He was the grandson of William Jennings, an owner-trainer who won the 1887 Preakness Stakes.Clark began his professional career in 1929 and got his first stakes winner with Liz Whitney Tippett's colt, Blue Cypress. Sill working well into his nineties, Clark holds the record for most wins by a trainer in the Delaware Handicap with four.